Bit and tap and die chuck.



W. L. PROCUNIER.

BIT AND TAP AND DIE CHUCK. APPLICATION FILED JUNE 1e, 1911.

1,087,796. Patented sep1.3,1912.

UNITED sTATEs PATENT oEEioE.

WILLIAM L. PROCUNIER, 0F CHICAGO, ILLINOIS.

BIT AND TAP ANI) DIE CHUCK.

Specification of Letters Patent.

Patented Sept. 3, 1912.

Application mea June 1e, 1911. serial no. 333,531'. I

To all whom it may camera.' A

Be it known that I, WILLIAM L. PRO- CUNIER, a citizen of -the UnitedStates, re

ksiding at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvementsin. 'Bit and Tap and Die Chucks,gof which 'the following is a specitication,' reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to pro- `vide a bit and tap chuck adapted to be ad- .Fig 2, is an axial section in a plane at right angles to that of Fig. 1. Fig. 3 is a transverse section at the line, 3, 3, on Fig.l :2. Fig. 4 is a section at the line, 4, 4, on Fig. 1. Fig. 5 is asection at the line, 5, 5, on Fig. 1,

with the cap removed. Fig. 6 1s an axial section of a modification of the device adapted forV holding a die.

Heretofore, so aras I am aware, tap and bit chucks designed to slip to avoid breakiing the tool and adjustable to adapt the driving grip to the strength of the tool, have accomplished such purpose by employing springs and means for tensioning them to vary the frictional engagement by which driving power is transmitted to the tool. In my present invention I avoid all such use of springs, by producing the pressure for trictional engagement by means of two engaged parts of very slow taper, so that the amount of movement inthe direction of the taper may be very large relatively to the amount of crowdingl or pressure-producing movement in the transverse direction, and may therebybe veryreadily and accurately observable and divisible into sensibly large units corresponding Vto relatively small dit- 'ferences in the size of the tool; and by making these twoslow tapered members of difthe slowvtaper by which the crowding is etfected,4 such two. members are not liable to become locked, as -would be liable to happen with two `equally slow-tapered members if both were metal.l By use-ofltiber for one of the two vmembers-'in quest-ion, I obtain also `the advantage of als'light compressibility in excess of that which would be afforded by metal in the same situation.

In the drawings, 1 is an exteriorly tapered spindle, adapted to be rictionally held in the ordinary manner in the tool holding i head of any drill press or lathe, said spindle having an axial bore to receive the spin-.

dle, 2, ofthe'chuck, proper, said spindle, 2, being positivelyv engaged with the spindle, 1, by the pin, 3, This spindle, 1, is the driving elementand is adapted for frictional engagement as hereinafter described, with the driven and tool holding element, 4, which at its `lower 'end is provided with means hereinafter described, for holding the tool. Theupperend of the element, 4, is axially bored to form an upwardly open,

cvlindrical chamber or shell, 5, into which the lower, enlarged end portion, 6, of the driving element, 1, project-s axially. enlarged endportion, 6, is made of very slow taper and terminates upwardly in an abrupt shoulder, 6", between whichand the lower end of the'spindle, 2, the centrally apertured head, 7*, Vof the interiorly threaded cap nut- 7, is engaged and stopped against longitudinal movement, while free to turn on the spindle.A The shell, l5, is exteriorly threaded for engagement with the ,cap nut, 7, which thus serves to move the element, 4, axially with respect to the slow tapered terminal, 6, of the element l. In the chamber, 5, in the annular space around the slow tapered terminal, 6, thereis lodged a plural-membered frictional transmitting element, 8. As illustrated, this element comprises two semi-annular members which' Said f members of the frictional transmitting element, 8, spreading said members and forcing them into frictional engagement with the shell,` 5, and causing them to transmit the a rotation of the driving element, 2, to the driven element, 4, with varying degrees of force, according to the degree of frictional engagement produced by the adjustment Vof the cap nut.l A jamb nut, l0, is preferably 10 provided `on the exteriorly threaded shell, 5,

below the cap nut, 7 for securing the said cap nut for any desired degree of frictional engagement of the part-s. The plural-membered frictional transmittingelement, 8, is preferably of liber, and although I do not limit myself to any exact proportions, the taper ofthe terminal, 6, should probably not exceed 1/25 of an inch to the inch; and with such slow taper, it is practicable, after the slow tapered terminal has been forced axially between the members of the frictional transmitting element, 8, sufficiently to produce adequate frictional engagement between said element and the walls of the cham-l ber, 5, ofthe driven element, 4, to drive a tap or drill of, say 1/32 of an inch, at the highestspeed adapted for its strength without causing slipping between the frictionally engaged parts, to further force said slow tapered terminal axially down between the members of the frictional transmitting element, a distance corresponding to substantially two threads of the cap nut, 7,-a total circumferential movement of nearly six inches-without producing permanent set of the fiber transmission element, and without requiring more power than can be readily exerted by the hand of the operator upon the cap nut, 7 and at such maximum adjustment I nd that the frictional engagement is adequate for driving a tap or drill of as'much as e of an inch diameter,-ten times the diameter of the smallest tool for which the chuck is adapted,-at the highest speed for which the strength of such J,Efinch tool is adequate, and that the frictional engagement adequate for driving such tool at such speed is still such that slipping will occur upon further increase of the resistance experienced by the tool. That is to say, with this device, adjustment can be made to adapt the same chuckfor driving with safety from tools from 1/32 of an inch diameter up to as large as 7/16 ol' an inch diameter, .by adjustments in steps of nearly 2; of an inch at the circumference of the cap nut, and hence easily observable, for each 1/32 of an inch increase in the diameter of the tool `Another feature of this invention consists in the means for holding the tool in the lov er end of the driven member, 4. It is well known that absolute uniformity .is not found in respecl to the relative dimensions of the round shank of the drill or tap andv tively engaged for driving.4 The tool is preferably centered by some engagement of the shank at its round portion, and is preferably driven by the positive engagement at its squared end ;V and it is important, therefore, that any device for engaging the tool should effect such engagement.positivelyfand defi# nitely both at the round portion and at the squared portion, and that neither engagementshould forest-all or defeat the other. For this purpose I provide in the lower end of'the member, 4;, a conical, downwardly open cavitygi The lower endA portion of said member, 4, containing said conical cavity is exteriorly threaded, and an interiorly threaded follower, 11, is screwed onto it, said follower having its cavity at the lower end conical, preferably with the same taper as the conical cavity, 4a.

In the conical cavity, 4a, there are lodged two jaws', 12, 12 exteriorly tapered conically to lit approximately the taper of the' conical chamber, 4a, 'and having their meeting faces notched to vengage the square end, 13a, of a tool shank, 13, of customary form.\

The two jaws, 12, 1 2, are engaged with theY member, 4, for positive rotation thereby, -by

means of the cross pin, 15, which is inserted 11, the rotation of the follower screwing it onto the member, 4, will cause the jaws, 16, whose upper bases rest up against the lower ybases of the jaws, 11, to force said jaws,

11, up into their conical seat in the member, 4 until said jaws are closed upon the squared end of the tool, and'that if when thisv happens, thel jaws, 16, have not yet vclosely grasped the round shank of the tool,

the `follower can be st illfurther screwed up until said round portion is thus firmly grasped by the lower jaws. On the other hand, ifthe jaws, 16, become closed firmly upon the round portion of the shank before the jaws, 11, have rmly grasped the squared end, thefollower can be screwed up untill the latter engagement is perfectly effected. Whenever, therefore, theo erator'nds the -follower tight, he is there v assured that the tool is not only grasped rml at its squared end for positive driving, ut also grasped firmly atY its round shank for centering.

A modification of this chuckto adapt it for carrying .thread cutting dies instead of through` the peri hery of said reduced end,

intruding into. t' ef usual recess, 19, in the periphery of-the'die, 18 for-holdingY the die 1n place.

1. A chuck cempri'sing two elements, one being a driving and the other a driven element, the driven element having tool-holding means; -a third elementV for frictional transmission lof rotary movement from the driving to thel driven element,one of said irst-mentioned two elements having a chambered terminal whichcentrally receives a terminal of the other, one of said' terminals i being slow-tapered, said third element being radially' expansible and contractible and interposed 1n said chamber between the wal-l thereof and the otherA terminal therein, the tapered terminal eeing positively engaged for rotation without rotary slipping with said radially expansible and contractible third element,- and means for forcin said tapered terminal in axial-direction with respect to said third element.

2, A chuck comprisin ltwo elements, one being a driving and the-other a driven element, the driven element having tool-holding means; a third element for' frictional` transmission of rotary movement from the driving 'to theldriven element-of different material from thev othertwo elements; one of said irst-'mentioned tool elementshaving a chambered terminal which -centrally receives a terminall of the other, one of said terminals being slow-tapered, said third element being radially expansible and contractible and interposed in said chamber between the wall thereof and the other terminal therein, the tapered terminal being -tapered terminal andthe driven element having tool holding means; a third element for frictional transmission of rotary movement from the driving to the driven element, the driven element'having a' cylindrical or non-tapered chamber into which the tapered terminal of the driving element extends, said third element being pluralthe tapered terminal, and means for'positively forcing said tapered terminal into said chamber.-

being a driving and the other a driven elefment, the driving element'havinga slowhaving a cylindrical or non-tapered chamber which centrally receives said terminal and having tool holding means; a third clement which is radially eXpansible for frictional transmission of rotary movement fromthe driving to the driven element, interposed in the annular interval in said cylindricall chamberaround the tapered l terminal therein and stopped o n the bottom thereof, and means for lpositively vforcing the ta ,ered terminal inward with respect to sai chamber.`

5. A. chuck comprising two elements, one being a driving and the other a driven element, the driven element having tool-hold-` ing means, one of said elements having a chambered terminal which centrally receives the terminal of the other, one of said terminals being slow-tapered; a third radially eXpansible .element of fiber for-frictional transmission of rotary movement fromA the the annularinterval 'in said. chamber around bottom of said chamber; means for poslsaid third'I element for rotation without rotary slipping of the one upon the "other, and means for ositively forcing such ta ered terminal vinward withv respect to sald chamber.

6. A chuck comprising a driving. member, having a` stem and a slow-tapered terminal and a driven member having a cylindrical or untapered chamber which centrally receives such terminal, and having tool holding means; a third element which is radiall expansible for frictional transmission o rotary movement from the driving to the driven element, said third element being interposed in said chamber around by which said slow-tapered terminal posiltively engages the third element forrf rotation without rotary slipping; a cap nut screwed onto the chambered-end of the irst element, having its head apertured for the stem of the driving element, and means for securing said cap nut, Y

7. A chuck com rising a driving element, having a stem an slow-tapered terminal, a driven element, hav' a chamber which centrally receives the s ow-tapered terminal and having tool-holding means below said membered and having its members interposed in the chamber at opposite sides ofdriving to the driven element interposed in the terminal therein,- and stopped on the said slow ta ered'terminal therein; means.

. 4. A chuck comprising two elements, one

tapered terminal-and the driven element v tively -enga-ging the tapered terminal with e.

chamber; a plural-membered and radially expansible element for rictional transmission of rotary movement from the driving element to the driven element, interposed in the chamber around said slow-tapered terminal, said terminal having means engaging between the members of said expansible ele-- ment for positively rot-ating said element with the `driving element,l and means fr positively forcing the tapered terminal axially with respect to the radially eXpansible element.

8. A chuck comprising a driving element, having a stein and an enlarged slow-tapered terminal, having an abrupt shoulder; a driven element, having a chamber which centrally receives the slow-tapered terminal and having tool-holding means below said chamber; a plural-membered and radially expansible element for frictional transmission of rotary movement from the driving element to the driven element, interposed in the chamber around said slow tapered terminal, said terminal having means engaging between the members of said expansible element for positively rotating said element with the driving element, said chamber being exteriorly threaded at its centrally apertured cap Inut, through whose aperture the stem of thedriving element protrudes and Whose thread engages the exterior thread of the chamber forl positively forcing the slow tapered terminal axially into said expansible element.

Iny testimony whereof,l I have hereunto set my hand at Chicago, Ill., this 10th day of June, 1911.

WILLIAM L. PROCUNIER.

Witnesses:

CHAs. S. BUR'mN,

LUCY I. STONE. 

